/*
The ultimate DHTML drop-down code
Nick Nettleton
www.computerarts.co.uk || www.fluid7.co.uk
--
Modifications to support NS6 browser, and adjustments by
Gil Pedersen
--
This must be the single most requested bit of code in the history of Computer Arts, so we've decided to make it user-friendly and adaptable for everyone. Stacks more goodies to come too - head to one of the above sites for regular infoa nd updates.
Works with v4 and v5 browsers - both IE and NS. Update for NS6 coming. Also, be aware there's no way to automatically centre layers in the window - a JS for this coming soon. In the meantime, stick with left-aligned.
Keep an eye out for update for NS6.
--
You can adapt, use and distribute this code under GNU public licence, as long as:
(1) You leave all the comment and credit lines in, including these ones
(2) You don't sell it for profit
--
If you want to tweak the code yourself, use the f7_droplayer to set the names of the dropdowns, and just call f7_showdrop(n) and f7_hdidedrop from onmouseover, onmouseout and other events. Swap n for the number of the layer as in the array.
--
Enjoy!!!
*/

if (document.getElementById){
	pre='document.getElementById("'; post='")'; style='.style'
} else if (document.all){
	pre='document.all.'; post=''; style='.style'
} else if (document.layers){
	pre='findElement("'; post='")'; style=''
}

function findElement(n, ly) {
	var curDoc = ly ? ly.document : document; var elem = curDoc[n];
	if (!elem) { for (var i=0;i<curDoc.layers.length;i++) {
		elem = findElement(n,curDoc.layers[i]); if (elem) return elem; }}
	return elem;
}

function getLayer(l) {
	return eval(pre + l + post)
}

function getLayerStyle(l) {
	var a=getLayer(l)
	if (a)
		return a=eval('a' + style);
	return null
}

function layerSetVis(l, s) {
	a=getLayerStyle(l)
	if (a) a.visibility = (s == 0) ? 'hidden' : 'visible'
}

function getClip(obj) {
	var clip=new Object()
	clip.left=-1;clip.top=-1;clip.width=-1;clip.height=-1
	if (obj) {
		if (document.layers) {
			// netscape 4 style
			clip.left=obj.left
			clip.width=obj.clip.width
			clip.top=obj.top
			clip.height=obj.clip.height
		}
		else if (obj.style) {
				if (obj.style.pixelLeft) {
					clip.left = obj.style.pixelLeft
					clip.top = obj.style.pixelTop
				}
				else {
					var t=obj
					clip.left=t.offsetLeft
					clip.top=t.offsetTop
					while(t.offsetParent) {
						t=t.offsetParent
						clip.left+=t.offsetLeft
						clip.top+=t.offsetTop
					}
				}
				clip.width=obj.offsetWidth
				clip.height=obj.offsetHeight
		}
	}
	return clip;
}

function fixPos(t,l) {
	if (t) {
		var clip=getClip(t);
		if(navigator.appVersion.indexOf("MSIE 5")>-1 && navigator.appVersion.indexOf("Mac")>-1) {
			clip.left+=parseInt(document.body.leftMargin) - 2
			clip.top+=parseInt(document.body.topMargin) - 2
		}
		l.style.left = clip.left+'px'
		l.style.top = (clip.top + clip.height - 1)+'px'
	}
}

//names of dropdowns stored here
f7_droplayer=new Array()
f7_droplayer[1]="linkpage1"
f7_droplayer[2]="linkpage2"
f7_droplayer[3]="linkpage3"
f7_droplayer[4]="linkpage4"
f7_droplayer[5]="linkpage5"



//simple browser check
f7_v4=(parseInt(navigator.appVersion)>=4 && parseInt(navigator.appVersion)<=5)?1:0
f7_ns=(document.layers && f7_v4)?1:0

//code for drops
function f7_showdrop(thelayer){
	f7_keep=thelayer;
	for(i=1;i<f7_droplayer.length;i++){  
		if(thelayer!=i) layerSetVis(f7_droplayer[i], 0);
	}
	f7_showitnow=1
	f7_showit(thelayer)
	}

function show_props(obj, obj_name) {
          var result = ""
          for (var i in obj)
                    result += obj_name + "." + i + " = " + obj[i] + "<br>"
          document.write(result);
          return result
}

function f7_showit(thelayer){
		var l=f7_droplayer[thelayer]
			var t=getLayer('lists'+thelayer);
			//if (t) show_props(document.body, 'document.body')
		if (f7_ns) {
			t=getLayer('lists'+thelayer);
			if (t) {
				//show_props(t, 'lists1')
				var f7_left = t.pageX
				var f7_top = t.pageY + t.clip.height
				eval('document.'+l+'.left=f7_left')
				eval('document.'+l+'.top=f7_top')
				}
			}
		else {
			fixPos(getLayer('lists'+thelayer), getLayer(l))
		}
		layerSetVis(l, 1);
	}

f7_hidecount=0;
function f7_timedhide() {
	f7_hidecount++
	setTimeout('f7_hidetimer()',500)
}
function f7_hidetimer() {
	f7_hidecount--
	if (!f7_hidecount)
		f7_hideall();
}

function f7_hidedrop(){
	f7_keep=-1; f7_timedhide()
	}

f7_keep=-1

function f7_hideall(){
	for(var i=1;i<f7_droplayer.length;i++){  
		f7_hideit=0; f7_checkmousepos(i)
		if(f7_keep!=i && f7_hideit)
			layerSetVis(f7_droplayer[i], 0);
		}
	}

//deal with cursor over layer
document.onmousemove = f7_getmousepos
if (f7_ns) document.captureEvents(Event.MOUSEMOVE)

function f7_getmousepos(e){
	if(e){f7_mousex=e.pageX; f7_mousey=e.pageY;}
	else if(event){f7_mousex=event.clientX; f7_mousey=event.clientY;}
	}

function f7_checkmousepos(i){
	var clip = getClip(getLayer(f7_droplayer[i]));
	f7_x_min=clip.left;
	f7_x_max=clip.left+clip.width;
	f7_y_min=clip.top;
	f7_y_max=clip.top+clip.height;
	
	if (f7_mousex>=f7_x_min && f7_mousex<=f7_x_max && f7_mousey>=f7_y_min && f7_mousey<=f7_y_max){
		f7_hideit=0; f7_timedhide()
		}
	else { f7_hideit=1 }
	return f7_hideit
	}